Salient White Elephant

May 5, 2009

Powered Bicycles in the City

Filed under: Brash Environmental Commentary, Electric Vehicle (EV), green technology — Salient White Elephant @ 6:41 pm

Soft, pastel colored cotton ropes move through the city driven by pulley wheels. If you get tired of pedaling, you just grab on to the rope and it pulls you along. This would be particularly useful in places like San Francisco where lots of people want to ride a bike, but the hills are just too steep. A person could pedal on the level areas, coast downhill, and hold the rope to go up hill.

Of course, you don’t actually grab hold of a rope, because that would make it hard to balance. There’s a mechanical device that is easily flipped over that grabs the rope and transfers the force in a way that doesn’t throw you off balance. And this also allows you to have both hands on the handlebars.

One of the nicest things about China was its bicycle transportation system. Of course, I don’t guess there’s much left of it now, thanks to the magic of capitalism and its ability to turn every corner of life into the dullest and most discouraging of chores. I believe this is what Adam Smith was referring to when he coined the phrase “the invisible butt of the free market economy”. But let me tell you something – you haven’t lived until you’ve traveled to your destination anywhere in the city alongside young girls that just stepped out of a fashion magazine and wise old leather-skinned men and women with impenetrable facial expressions that have seen hardships you can’t imagine… everybody cruising along at about 15 miles per hour, no diesel smoke stinging your nostrils, birds chirping, and the nicest widest bike path you can imagine meandering through the city. There wasn’t a road you needed to travel that didn’t have one of these cadillac bike paths, for in 1990s China, the bicycle was the mode of transportation, and everything else had to get out of the way. And as for those wise old men and women and the emotional burdens of past hardship they carried, seems like most of them usually had the most calm and content aura, impenetrable though it was. How could that be? I don’t know, but I think it had something to do with the magic of riding a bicycle, the healthy bodies that bike riding produced (you couldn’t find an obese person in China in those days), the chirping birds, and most of all, the fact that you were king of the road.

… old stogies I have found,

shooooort, and not to big around I’m a…

maaaaan o means by no means,

King o the Roooad!


April 15, 2009

Dirt Cheap Ultra-Simple Efficient Third World Water Transport Pump

Here is a surprisingly efficient and extremely simple pump for transporting clean drinking water from one place to another. The diagrams below show how to move water in the horizontal direction, but the pump may also be designed to move water from a low elevation to a high elevation. (It can pump water up a hill.)

Third World Water Transport Pump

The rotating arms of this pump are probably driven by electric motors. An inexpensive micro-computer keeps the arms synchronized so that each arm is always 120 degrees out of phase with its neighbors. (It should be easy to superimpose a clock synchronizing pulse onto the power lines that go alongside the hose to feed the electric motors. In this case, each microcomputer that controls each motor operates independently, and there’s no need for the micro-computers to communicate with one another.) Though I can’t prove it mathematically, I think the efficiency of this pump will be quite good. Generation of turbulence in the water should be about as low as it could be. And besides this, what other losses are present in the system? The heat that is generated by the motors will not be more than with any other kind of pump, and the friction with the hose is low because the hose is supported by pulley wheels.

Here’s a sequence of images that show the motion of the hose in detail. If the arms rotate with clockwise polarity, then water will be transported from right to left:

Detailed Motion of Third World Water Transport Pump

Variations on this idea may include a long belt that mechanically links the rotating arms together. (This is probably not a very good idea, but it might be a good choice if a completely mechanical wind pumping system is desired.) Also, PVC pipe may replace the hose. In this case a PVC segment is connected to its neighbors with a flexible joint (like or short piece of hose), or else the diameter of the end of its neighbor pipe is large enough for the end of the PVC segment in question to extend to a point inside of the end of the neighbor pipe.

The diagrams show the arms rotating in the plane of the hose or pipe, but they may rotate in the orthogonal plane instead. In this case they mimick the motion of the High Efficiency Helical Liquid Pump. But maybe the best way to move the hose is to use a crankshaft with a “piston rod” that has a fixed connection to the hose:

Third World Water Transport Pump, Crankshaft Version

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